         parent-leftmost-sexpr  (and parent-leftmost-node
                                     (not
                                      (#{:uneval}
-                                      (b/tag parent-leftmost-node)))
-                                    (b/sexpr parent-leftmost-node))]
+                                      (z/tag parent-leftmost-node)))
+                                    (z/sexpr parent-leftmost-node))]
     (and first-node?
          (= :require parent-leftmost-sexpr)
          (= node-sexpr old-sym-prefix-libspec))))
 
 (defn- contains-sym? [old-sym node]
-  (when-not (#{:uneval} (b/tag node))
-    (when-let [node-sexpr (b/sexpr node)]
+  (when-not (#{:uneval} (z/tag node))
+    (when-let [node-sexpr (z/sexpr node)]
       (or
        (= node-sexpr old-sym)
        (libspec-prefix? node node-sexpr old-sym)))))

            [me.raynes.fs :as fs]
            [rewrite-clj.zip :as z]
            [rewrite-clj.node :as n]
            [rewrite-clj.zip.base :as b]
            [rewrite-clj.parser :as parser]
            [rewrite-clj.reader :as reader])
  (:import (java.io File FileNotFoundException)))

  (str/replace source-sans-ns symbol-regex (partial source-replacement old-sym new-sym)))

(defn- after-platfrom-marker? [platform node]
  (when-not (#{:uneval} (z/tag node))
    (= platform (z/sexpr (z/left node)))))

(defn- find-and-replace-platform-specific-subforms [platform ns-loc]
  (loop [loc         ns-loc
